Mastering tools and systems and methods for forming a cell on the mastering tools

ABSTRACT

Mastering tools and systems and methods for forming a cell on the mastering tools are provided. An exemplary method includes emitting a first laser light pulse from a laser for a first predetermined time interval such that at least a portion of the first laser light pulse forms the cell on the mastering tool. The cell has an opening size within a range of 10-100 micrometers and an aspect ratio less than or equal to 1.25.

BACKGROUND OF THE INVENTION

Textures on mastering tools have been formed using techniques such asgrit blasting, electro-discharge texturing (EDT), chemical etching, andmechanical engraving. However, manufacturers utilizing the foregoingtechniques have been unable to form cells having: (i) an opening sizewithin a range of 10-100 micrometers, and (ii) an aspect ratio less thanor equal to 1.25 wherein an aspect ratio is a size of a cell openingdivided by a depth of the cell, which is desirable for mastering toolsutilized to form textures on film.

Accordingly, the inventors herein have recognized a need for improvedsystem and method that forms a cell on a mastering tool having anopening size within a range of 10-100 micrometers, and an aspect ratioless than or equal to 1.25.

BRIEF DESCRIPTION OF THE INVENTION

A method for forming a cell on a mastering tool in accordance with anexemplary embodiment is provided. The method includes emitting a firstlaser light pulse from a laser for a first predetermined time intervalsuch that at least a portion of the first laser light pulse forms thecell on the mastering tool. The cell has an opening size within a rangeof 10-100 micrometers and an aspect ratio less than or equal to 1.25.

A system for forming a cell on a mastering tool in accordance withanother exemplary embodiment is provided. The system includes a laserconfigured to emit a first laser light pulse for a first predeterminedtime interval such that at least a portion of the first laser lightpulse forms the cell on the mastering tool. The cell has an opening sizewithin a range of 10-100 micrometers and an aspect ratio less than 1.25.

A mastering tool in accordance with another exemplary embodiment isprovided. The mastering tool includes a cylindrical drum having at leastone cell. The cell has an opening size within a range of 10-100micrometers and an aspect ratio less than or equal to 1.25.

A mastering tool in accordance with another exemplary embodiment isprovided. The mastering tool includes a plate member having at least onecell. The cell has an opening size within a range of 10-100 micrometersand an aspect ratio less than or equal to 1.25.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic of a system for forming a plurality of cells on amastering tool utilizing cell geometry randomization in accordance withan exemplary embodiment;

FIG. 2 is a schematic of a plurality of cells on a mastering tool havinga hexagonal close packed pattern without cell geometry randomization;

FIG. 3 is a schematic of a plurality of cells on a mastering tool havinga hexagonal close packed pattern with cell geometry randomization;

FIG. 4 is a schematic of exemplary laser light pulse power levelsutilized in the system of FIG. 1 to form cells on a mastering tool;

FIG. 5 is a graph illustrating an exemplary distribution of cell openingsizes of a plurality of cells formed on a mastering tool;

FIG. 6 is another graph illustrating another exemplary distribution ofcell opening sizes of a plurality of cells formed on a mastering tool;

FIG. 7 is a schematic illustrating an exemplary focal point of a laserlight pulse at an outer surface of a mastering tool;

FIG. 8 is a cross-sectional schematic of a portion of a mastering toolillustrating a cell formed on the mastering tool by the laser lightpulse of FIG. 7;

FIG. 9 is a schematic illustrating another exemplary focal point ofanother laser light pulse at an outer surface of a mastering tool;

FIG. 10 is a cross-sectional schematic of a portion of a mastering toolillustrating a cell formed on the mastering tool by the laser lightpulse of FIG. 9;

FIG. 11 is a table of exemplary operational parameters of the system ofFIG. 1, utilizing a YAG laser, for forming a plurality of cells on amastering tool;

FIG. 12 is a table of exemplary operational parameters of an alternativeembodiment of the system of FIG. 1, utilizing a Ytterbium fiber laser,for forming a plurality of cells on a mastering tool;

FIGS. 13-17 are flowcharts of a method for forming a plurality of cellson a mastering tool utilizing the system of FIG. 1 in accordance withanother exemplary embodiment;

FIG. 18 is a schematic of a system for forming a plurality of cells on amastering tool utilizing cell placement randomization in accordance withanother exemplary embodiment;

FIG. 19 is a schematic of a plurality of cells on a mastering toolhaving cell placement randomization;

FIG. 20 is a schematic of a plurality of amplitude values utilized bythe system of FIG. 18 to form a plurality of cells on a mastering tool;

FIG. 21 is a graph illustrating an exemplary distribution of cellplacement errors of a plurality of cells formed on a mastering toolutilizing the plurality of amplitude values of FIG. 20;

FIG. 22 is a schematic of another plurality of amplitude values utilizedby the system of FIG. 18 to form a plurality of cells on a masteringtool;

FIG. 23 is a graph illustrating another exemplary distribution of cellplacement errors of a plurality of cells formed on a mastering toolutilizing the plurality of amplitude values of FIG. 22;

FIG. 24 illustrates an exemplary plurality of placement lines on whichcenter points of a plurality of cells are disposed on a mastering tool;

FIG. 25 illustrates another exemplary plurality of placement lines onwhich center points of a plurality of cells are disposed on a masteringtool;

FIGS. 26-30 are flowcharts of a method for forming a plurality of cellson a mastering tool utilizing the system of FIG. 18 in accordance withanother exemplary embodiment;

FIG. 31 is a schematic of a system for forming a plurality of cells on amastering tool utilizing both cell placement randomization and cellgeometry randomization in accordance with another exemplary embodiment;

FIG. 32 is a schematic of a plurality of cells on a mastering toolhaving cell placement randomization and cell geometry randomization;

FIGS. 33-38 are flowcharts of a method for forming a plurality of cellson a mastering tool utilizing the system of FIG. 31 in accordance withanother exemplary embodiment;

FIG. 39 is a schematic of a system for forming a plurality of cells on amastering tool in accordance with another exemplary embodiment; and

FIGS. 40-41 are flowcharts of a method for forming a plurality of cellson a mastering tool utilizing the system of FIG. 39 in accordance withanother exemplary embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, a system 20 forming a plurality of cells on amastering tool 24 is provided. A cell is defined as a cavity thatextends from an outer surface of a mastering tool into a mastering tool.Each cell has an aspect ratio that is defined as a depth of a celldivided by a size of a cell opening. A mastering tool is defined as anytool having a plurality of cells that are configured to form a texturedsurface on another material. For example, a mastering tool can define atextured surface on a film or a sheet of material. Further, a shape orconfiguration of the mastering tool can vary based on the desiredapplication. In the illustrated exemplary embodiment, the mastering tool24 comprises a cylindrical drum. It an alternative exemplary embodiment,the mastering tool comprises a plate (not shown). In one exemplaryembodiment, the mastering tool is constructed from steel with an outerchrome surface. In another exemplary embodiment, the mastering tool isconstructed from steel with an outer ceramic surface. An advantage ofthe system 20 is that the system 20 utilizes a geometry randomizationmethodology to vary an aspect ratio of cells formed on the masteringtool 24 by varying a power level of laser light pulses contacting themastering tool 24. As a result, the mastering tool 24 has a texturedsurface that can form a textured film that does not have the undesirablebanding and patterns discussed above. The system 20 includes a laser 30,a power supply 32, a light attenuating device 34, a signal generator 35,mirrors 36, 38, 40, a focusing lens 42, a carriage device 44, a focusingdevice 46, a motor 48, a position sensor 50, and a controller 52.

The laser 30 is provided to generate a plurality of laser light pulsesthat are used to form a plurality of cells on the mastering tool 24. Inthe illustrated exemplary embodiment, the laser 30 comprises a singlemode Q-switched YAG laser. It should be noted that in alternativeembodiments, the laser 30 can comprise any known laser capable offorming cells on a mastering tool. For example, in an alternativeembodiment the laser 30 comprises a single mode continuous-modeYtterbium fiber laser. The laser 30 is controlled via the control signalfrom the controller 52. Further, the laser 30 receives electrical powerfrom the power supply 32. The laser 30 includes a YAG chamber 60,mirrors 62, 64, a plate 66, a Q-switch 70, and a housing 72 configuredto hold the foregoing components.

The YAG chamber 60 is provided to generate a laser light beam inresponse to electrical power being received from the power supply 32.The light propagates through a plate 66 having an aperture 68 extendingtherethrough. The diameter of the light beam passing through theaperture 68 has a diameter and a mode shape that is substantiallydependent on the diameter of the aperture 68. In one exemplaryembodiment, the diameter of the aperture 68 is 1 millimeter. Of course,the aperture 68 could have a diameter less than or greater than 1millimeter. The laser light beam is intermittently switched through theQ-switch 70 as laser light pulses to the mirror 62 in response to theQ-switch 70 receiving control signals from the controller 52. The mirror62, the mirror 64, and the YAG chamber 60 are utilized to generate acontinuous laser light beam as known by those skilled in the art. Theaperture 68 in the plate 66 controls the mode, size, and quality of thelaser light beam. The Q-switch 70 is utilized to emit relatively highintensity laser light pulses toward the light attenuating device 34,instead of the continuous laser light beam.

The signal generator 35 is provided to generate a plurality of amplitudevalues that are received by the controller 52 and subsequently utilizedby the controller 52 to induce the light attenuating device 34 to varypower levels of laser light pulses utilized to form a plurality of cellson the mastering tool 24. It should be noted that by varying a powerlevel of laser light pulses, the cell opening sizes and the cell depthsof cells formed on the mastering tool 24 can be varied.

The light attenuating device 34 is provided to attenuate power levels ofa plurality of laser light pulses received from the laser 30, based oncontrol signals from the controller 52. In particular, the lightattenuating device 34 receives each laser light pulse at a power levelfrom the laser 30 and attenuates the laser light pulse to another powerlevel, based on the control signal from the controller 35. The lightattenuating device 34 is disposed between the laser 30 and the mirror36. Referring to FIG. 4, the light attenuating device 34, varies a powerlevel of laser light pulses 96, 98, 100 between a maximum power level(Pmax) and a minimum power level (Pmin).

Referring again to FIG. 1, the mirror 36 is provided to receive laserlight pulses from the light attenuating device 34 and to reflect thelaser light pulses to the mirror 38. In the illustrated embodiment, themirror 36 is a stationary mirror. However, in an alternative embodiment,the mirror 36 is configured as a moveable mirror whose position can bechanged based on a control signal from the controller 52, to vary adirection of reflected laser light pulses toward the mirror 38.

The mirror 38 is provided to receive laser light pulses from the mirror36 and to reflect the laser light pulses to the mirror 40. In theillustrated embodiment, the mirror 38 is a stationary mirror. However,in an alternative embodiment, the mirror 38 is configured as a moveablemirror whose position can be changed based on a control signal from thecontroller 52, to vary a direction of reflected laser light pulsestoward the mirror 40.

The mirror 40 is provided to receive laser light pulses from the mirror38 and to reflect the laser light pulses to the focusing lens 42. Themirror 40 is coupled to the carriage device 44 that moves the mirror 40generally parallel to the mastering tool 46 from an end 25 to an end 26of the mastering tool 24.

An optical component, such as the focusing lens 42 for example, isprovided to receive a plurality of laser light pulses from the mirror 40and to focus each of the laser light pulses. In one exemplaryembodiment, the focusing lens has a focal length of 40 millimeters. Inalternative embodiments, the focusing lens 42 has a focal length of 50millimeters and 80 millimeters. Of course, the focusing lens 42 can havefocal lengths between 40-80 millimeters, or less than 40 millimeters, orgreater than 80 millimeters. Of course, in alternative embodiments, theoptical component can be a group or a system of lenses having thefunctionality of focusing the laser light pulses on the mastering tool.Further, the optical component can comprise an optical fiber (not shown)with a predetermined facet which delivers the laser light pulses to themastering tool to form cells on the mastering tool.

The focusing device 46 is provided to move the mirror 40 either inwardlyor outwardly towards the mastering tool 24 to adjust a focal point ofthe laser light pulse relative to the mastering tool 24, based on acontrol signal from the controller 52. The focusing device 46 isphysically coupled to both the carriage device 44 and the focusing lens42 and is electrically coupled to the controller 52. Referring to FIGS.7 and 8, during operation, the focusing device 46 can move the focusinglens to a first position (F1) such that the focusing lens 42 focuses alaser light pulse 130 to a focal point 132 that is at a predeterminedoptimal depth within the mastering tool 24. The laser light pulse 130forms a cell 150 on the mastering tool 24 having a width (W1) and adepth (D1), wherein the aspect ratio is relatively high. Referring toFIGS. 9 and 10, further during operation, the focusing device 46 canmove the focusing lens 42 to another position (F2) such that thefocusing lens 42 focuses a laser light pulse 140 to a focal point 142that is at another predetermined depth within the mastering tool 24. Thelaser light pulse 140 forms a cell 152 on the mastering tool 24 having awidth (W2) and a depth (D2), wherein the width (W2) is greater than thewidth (W1), and the depth (D2) is less than the depth (D1).

Referring to FIG. 1, the carriage device 44 is provided to move themirror 40, the focusing device 46, and the focusing lens 42 from the end25 to the end 26 of the mastering tool 24, based on the control signalfrom the controller 52. It should be noted that during operation whenthe carriage device 44 is stopped at a position relative to themastering tool 24, the mastering tool 24 can be rotated such that laserlight pulses can form a plurality of cells around a circumference of themastering tool 24, before the carriage device 44 moves to anotherposition relative to the mastering tool 24. Of course, in an alternativeembodiment, the formation of a plurality of cells around the masteringtool 24 is obtained by continuously stepping the carriage device 44relative to the mastering tool 24. In the alternative embodiment, theplurality of cells would be formed along a helical path on the masteringtool 24 rather than a circumferential path on the mastering tool 24. Thecarriage device 44 is physically coupled to the mirror 40, the focusingdevice 46, and the focusing lens 42, and is electrically coupled to thecontroller 52.

It should be noted that in an alternative embodiment, the laser 72 andthe light attenuating device 34 could be directly coupled to thecarriage device 44. In this alternative embodiment, the laser 72 emitslaser light pulses to the light attenuating device 34 which furtherdirects the laser light pulses to the focusing lens 42. The focusinglens 42 directs the laser light pulses to the mastering tool 24 to formcells on the mastering tool 24.

The motor 48 is provided to rotate the mastering tool 24 about an axis49 at a predetermined speed, in response to control signal from thecontroller 52. The motor 48 is physically coupled of the mastering tool24 and electrically coupled to the controller 52.

The position sensor 50 is provided to generate a signal indicative of arotational position of the mastering tool 24. The position sensor 50 isphysically coupled to the mastering tool 24 and electrically coupled tothe controller 52.

The controller 52 is provided to control operation of the components ofthe system 20 for forming a plurality of cells on the mastering tool 24.In particular, the controller 52 is configured to control operation ofthe laser 30, the carriage device 44, the focusing device 46, and themotor 48. Further, the controller 52 is configured to receive amplitudevalues from the signal generator 35 for controlling the lightattenuating device 34 to vary a power level of emitted laser lightpulses from the device 34. Further, the controller 52 is configured toreceive position signals from the position sensor 50, which can beutilized to accurately position the cells at desired rotationalpositions on the mastering tool 24 at desired rotational positions. Thecontroller 52 includes a central processing unit (CPU), a computerreadable medium such as a read-only memory (ROM), a random access memory(RAM), and an input-output (I/O) interface (not shown). The CPU executesthe software algorithms stored in the computer readable medium forimplementing the control methodology described below with respect tosystem 20.

Referring to FIG. 3, a brief explanation of a layout of a plurality ofcells on a mastering tool with cell geometry randomization will beexplained. Cell geometry randomization refers to the methodology ofutilizing laser light pulses with varying power levels to generate cellshaving varying aspect ratios (e.g., varying cell opening sizes, varyingcell depths, or both) in accordance with a predetermined distribution.As shown, the plurality of cells 82 on a mastering tool have varyingcell opening sizes when cell geometry randomization is utilized. Inparticular, the cells 81, 82, 83 centered along line 84 have varyingcell opening sizes. It should be noted that for purposes of simplicity,the line 84 is shown in a 2-D view. Further, the cells 85, 86, 87centered along line 88 have varying cell opening sizes. In contrast,referring to FIG. 2, when cell geometry randomization is not utilized aplurality of cells 80 on a mastering tool can have substantiallyidentical cell opening sizes. It should also be noted that the packingpattern of the cells can be varied according to a desired opticalproperties. For example, the packing pattern can be a square packingpattern, a face-centered-cubic packing pattern, a hexagonal packingpattern, or any combination of the foregoing packing patterns.

Referring to FIG. 5, a graph 110 illustrates an exemplary distributionof cell opening sizes on a mastering tool that can be obtained utilizingthe system 20. In particular, the histogram bar 112 indicates that 12percent of the cells on a mastering tool have a cell opening size of 15microns. Further, the graph 110 illustrates that a laser light pulsehaving a power level (P1_1) is utilized to form each cell having a cellopening size of 15 microns. The graph 110 also indicates that anamplitude value (S1_1) is utilized to induce the light attenuatingdevice 34 to output a laser light pulse having the power level (P1_1).

Further, in particular, a histogram bar 114 indicates that seven percentof the cells on the mastering tool have a cell opening size of 25microns. Further, the graph 110 illustrates that a laser light pulsehaving power level (P1_11) is utilized to form each cell having a cellopening size of 25 microns. The graph 110 also indicates that anamplitude value (S1_11) is utilized to induce the light attenuatingdevice 34 to output a laser light pulse having the power level (P1_11).

Referring to FIG. 6, a graph 120 illustrates another exemplarydistribution of cell opening sizes on a mastering tool that can beobtained utilizing the system 20. In particular, the histogram bar 122indicates that 23 percent of the cells on a mastering tool have a cellopening size of 15 microns. Further, the graph 120 illustrates that alaser light pulse having a power level (P2_1) is utilized to form eachcell having a cell opening size of 15 microns. The graph 120 alsoindicates that an amplitude value (S2_1) is utilized to induce the lightattenuating device 34 to output a laser light pulse having the powerlevel (P2_1).

Further, in particular, a histogram bar 124 indicates that five percentof the cells on a mastering tool have a cell opening size of 18 microns.Further, the graph 120 illustrates that a laser light pulse having apower level (P2_4) is utilized to form each cell having a cell openingsize of eighteen microns. The graph 120 also indicates that an amplitudevalue (S2_4) is utilized to induce the light attenuating device 34 tooutput a laser light pulse having the power level (P2_4).

Referring to FIG. 11, a table 160 illustrating empirically determinedoperational parameters associated with the system 20 for forming aplurality of cells on the mastering tool 24 is illustrated. Further, theoperational parameters are associated with forming cells on a chromesurface of the mastering tool 24. Still further, the operationalparameters were determined utilizing a YAG laser. In particular, thetable 160 indicates that cells can be formed having a cell opening sizein a range of 10-25 microns, with an aspect ratio in a range of 0-1.25,when the following operational parameters are utilized: (i) focal lengthof focusing lens 42 equals 40 millimeters, (ii) average power of laserlight pulses reaching the mastering tool is 1-5 Watts, (iii) a laserlight pulse length equals 6.1 microseconds, and (iv) a working range fora focal position on the mastering tool is ±30 microns. The working rangerepresents a tolerance range for a distance between the focusing lensand a surface of the mastering tool (e.g., distance F1 in FIG. 7) thatwill retain cell uniformity and integrity.

The table 160 further indicates that a cell can be formed on themastering tool 24 having a cell opening size in a range of 15-35microns, with an aspect ratio in a range of 0-1.0, when the followingoperational parameters are utilized: (i) focal length of focusing lens42 equals 50 millimeters, (ii) average power of a laser light pulses is3-8 Watts, (iii) a laser light pulse direction equals 6.1 microseconds,and (iv) a working range for a focal position on the mastering tool is+60 microns.

The table 160 further indicates that a cell can be formed having a cellopening size in a range of 25-50 microns, with an aspect ratio in arange of 0-0.9, when the following operational parameters are utilized:(i) focal length of focusing lens 42 equals 80 millimeters, (ii) averagepower of laser light pulses is 6-10 Watts, (iii) a laser light pulseduration equals 6.1 microseconds, and (iv) a working range for a focalposition on the mastering tool is ±100 microns.

The table 160 further indicates that a cell can be formed having a cellopening size in a range of 50-100 microns, with an aspect ratio in arange of 0-0.5, when the following operational parameters are utilized:(i) focal length of focusing lens 42 equals 80 millimeters, (ii) averagepower of laser light pulses is 10-20 Watts with multiple pulses formingthe cell, (iii) a laser light pulse duration equals 8.3 microseconds,and (iv) a working range for a focal position on the mastering tool is±100 microns.

Referring to FIG. 12, a table 170 illustrating empirically determinedoperational parameters associated with the system 20 for forming aplurality of cells on a ceramic mastering tool is illustrated. Stillfurther, the operational parameters were determined utilizing aYtterbium fiber laser instead of laser 30. In particular, the table 170indicates that cells can be formed having a cell opening size in a rangeof 10-25 microns, with an aspect ratio in a range of 0-1.25, when thefollowing operational parameters are utilized: (i) focal length offocusing lens 42 equals 40 millimeters, (ii) average power of laserlight pulses is 1-15 Watts, (iii) a laser light pulse duration equals2.8 microseconds, and (iv) a working range for a focal position on themastering tool is ±30 microns.

The table 170 further indicates that a cell can be formed having a cellopening size in a range of 15-35 microns, with an aspect ratio in arange of 0-1.0, when the following operational parameters are utilized:(i) focal length of focusing lens 42 equals 50 millimeters, (ii) averagelaser power is 5-25 Watts, (iii) a laser light pulse duration equals 3.3microseconds, and (iv) a working range for a focal position on themastering tool is ±60 microns.

The table 170 further indicates that a cell can be formed having a cellsize opening in a range of 25-50 microns, with an aspect ratio in arange of 0-0.9, when the following operational parameters are utilized:(i) focal length of focusing lens 42 equals 80 millimeters, (ii) averagepower of laser light pulses is 15-50 Watts, (iii) a laser light pulseduration equals 3.7 microseconds, and (iv) a working range for a focalposition on the mastering tool is ±100 microns.

The table 170 further indicates that a cell can be formed having a cellopening size in a range of 50-100 microns, with an aspect ratio in arange of 0-0.5, when the following operational parameters are utilized:(i) focal length of focusing lens 42 equals 80 millimeters, (ii) averagepower of laser light pulses is 50-100 Watts with multiple pulses formingthe cell, (iii) a laser light pulse duration equals 3.7 microseconds,and (iv) a working range for a focal position on the mastering tool is±100 microns.

Referring to FIGS. 13-17, a method for forming a plurality of cells onthe mastering tool 24 utilizing the system 20 will now be explained. Inparticular, for purposes of simplicity, the method will describe thesteps for forming first and second cells on the mastering tool 24utilizing the system 20. It should be noted that steps 180-210 describeutilizing a single laser light pulse for forming each respective cell onthe mastering tool 24. Still further, the steps 212-242 are optionalsteps that would only be utilized when additional laser light pulses areutilized for forming the first and second cells on the mastering tool24. Still further, it should be noted, that when the system 20 forms atextured surface on the mastering tool 24, the system 20 would form aplurality of additional cells in the mastering tool 24 utilizing stepssimilar to those described below.

At step 180, the controller 52 induces the motor 48 to rotate themastering tool 24.

At step 181, the position sensor 50 generates a first signal indicativeof a first rotational position of the mastering tool 24 that is receivedby the controller 52.

At step 182, the controller 52 generates a second signal having anamplitude that is based on a first amplitude value when the masteringtool 24 is at the first rotational position. The first amplitude valueis one of a plurality of amplitude values associated with apredetermined distribution of cell opening sizes within a range of cellopening sizes for the mastering tool 24.

At step 184, the controller 52 generates a third signal to induce thelaser 30 to emit a first laser light pulse having a first power leveltoward the light attenuating device 34 when the mastering tool 24 is atthe first rotational position.

At step 186, the light attenuating device 34 attenuates the first laserlight pulse to a second power level in response to the second signal.

At step 188, the mirror 36 reflects the first laser light pulse to themirror 38.

At step 190, the mirror 38 reflects the first laser light pulse to themirror 40.

At step 192, the mirror 40 reflects the first laser light pulse to thefocusing lens 42.

At step 194, the focusing lens 42 focuses the first laser light pulse ona first location of the mastering tool 24 such that the first laserlight pulse forms a first cell having a first cell opening size at thefirst location on the mastering tool 24.

At step 196, the position sensor 50 generates a fourth signal indicativeof a second rotational position of the mastering tool 24 that isreceived by the controller 52.

At step 198, the controller 52 generates a fifth signal having anamplitude that is based on a second amplitude value for controlling thelight attenuating device 34 when the mastering tool 24 is at the secondrotational position. The second amplitude value is one of the pluralityof amplitude values associated with the predetermined distribution ofcell opening sizes.

At step 200, the controller 52 generates a sixth signal to induce thelaser 30 to emit a second laser light pulse having a third power leveltoward the light attenuating device 34 when the mastering tool 24 is atthe second rotational position.

At step 202, the light attenuating device 34 attenuates the second laserlight pulse to a fourth power level in response to the fifth signal.

At step 204, the mirror 36 reflects the second laser light pulse to themirror 38.

At step 206, the mirror 38 reflects the second laser light pulse to themirror 40.

At step 208, the mirror 40 reflects the second laser light pulse to thefocusing lens 42.

At step 210, the focusing lens 42 focuses the second laser light pulseon a second location of the mastering tool 24 such that the second laserlight pulse forms a second cell having a second cell opening size at thesecond location on the mastering tool 24.

At step 212, the position sensor 50 generates a seventh signalindicative of the first rotational position of the mastering tool 24that is received by the controller 52.

At step 214, the controller 52 generates an eighth signal having anamplitude that is based on the first amplitude value associated with thepredetermined distribution of cell opening sizes when the mastering tool24 is at the first rotational position, for controlling the lightattenuating device 34.

At step 216, the controller 52 generates a ninth signal to induce thelaser 30 to emit a third laser light pulse having a fifth power leveltoward the light attenuating device 34 when the mastering tool 24 is atthe first rotational position.

At step 218, the light attenuating device 34 attenuates the third laserlight pulse to a sixth power level in response to the eighth signal.

At step 220, the mirror 36 reflects the third laser light pulse to themirror 38.

At step 222, the mirror 38 reflects the third laser light pulse to themirror 40.

At step 224, the mirror 40 reflects the third laser light pulse to thefocusing lens 42.

At step 226, the focusing lens 42 focuses the third laser light pulse onthe first location of the mastering tool 24 such that the third laserlight pulse further forms the first cell.

At step 228, the position sensor 50 generates a tenth signal indicativeof the second rotational position of the mastering tool 24 that isreceived by the controller 52.

At step 230, the controller 52 generates an eleventh signal having anamplitude that is based on the second amplitude value associated withthe predetermined distribution of cell opening sizes when the masteringtool 24 is at the second rotational position, for controlling the lightattenuating device 34.

At step 232, the controller 52 generates a twelfth signal to induce thelaser 30 to emit a fourth laser light pulse having a seventh power leveltoward the light attenuating device 34 when the mastering tool 24 is atthe second rotational position.

At step 234, the light attenuating device 34 attenuates the fourth laserlight pulse to an eighth power level in response to the eleventh signal.

At step 236, the mirror 36 reflects the fourth laser light pulse to themirror 38.

At step 238, the mirror 38 reflects the fourth laser light pulse to themirror 40.

At step 240, the mirror 40 reflects the fourth laser light pulse to thefocusing lens 42.

At step 242, the focusing lens 42 focuses the fourth laser light pulseon the second location of the mastering tool 24 such that the fourthlaser light pulse further forms the second cell. After step 242, themethod is exited.

Referring to FIG. 18, a system 250 for forming a plurality of cells on amastering tool 254 is provided. An advantage of the system 250 is thatthe system 250 utilizes a cell placement randomization methodology tovary a placement of the cells relative to circumferential lines on themastering tool by varying a position of laser light pulses contactingthe mastering tool with respect to the circumferential lines. As aresult, the mastering tool 254 has a textured surface that can form atextured film that does not have undesirable banding and patternsdiscussed above. The system 250 includes a laser 260, a power supply262, mirrors 264, 266, 268, a signal generator 270, an actuator 272, afocusing lens 274, a carriage device 276, a focusing device 278, a motor280, a position sensor 282, and the controller 284.

The laser 260 is provided to generate a plurality of laser light pulsesthat are used to form a plurality of cells on the mastering tool 254. Inthe illustrated exemplary embodiment, the laser 260 comprises a singlemode Q-switched YAG laser having a substantially similar structure aslaser 30. It should be noted that in alternative embodiments, the laser260 comprises any known laser capable of forming cells on a masteringtool. For example, in an alternative embodiment the laser 260 cancomprise a single mode continuous-mode Ytterbium fiber laser. The laser260 is controlled via the control signal from the controller 284.Further, the laser 260 receives electrical power from the power supply262.

The mirror 264 is provided to receive laser light pulses from the laser260 and to reflect the laser light pulses to the mirror 266. In theillustrated embodiment, the mirror 266 is a stationary mirror. However,in an alternative embodiment, the mirror 266 is configured as a moveablemirror whose position can be changed based on a control signal from thecontroller 284, to vary a direction of reflected laser light pulsestoward the mirror 266.

The mirror 266 is provided to receive laser light pulses from the mirror264 and to reflect the laser light pulses to the mirror 268. In theillustrated embodiment, the mirror 266 is a stationary mirror. However,in an alternative embodiment, the mirror 266 is configured as a moveablemirror whose position can be changed based on a control signal from thecontroller 284, to vary a direction of reflected laser light pulsestoward the mirror 268.

The mirror 268 is provided to receive laser light pulses from the mirror266 and to reflect the laser light pulses to the focusing lens 274. Themirror 268 is coupled to the carriage device 276 that moves the mirror268 generally parallel to the mastering tool 254 from an end 253 to anend 255 of the mastering tool 254. The actuator 272 is operable acoupled to the mirror 268 and is provided to rotate the mirror 268 todesired operational positions, based upon control signals from thecontroller 284.

The signal generator 270 is provided to generate a plurality ofamplitude values that are received by the controller 284 andsubsequently utilized by the controller 284 to generate control signalsto induce the actuator 272 to move the mirror 268 to desired operationalpositions to form the plurality of cells at desired locations on themastering tool 254. It should be noted that by varying the operationalposition of the mirror 268, the placement of the plurality of cells onthe mastering tool 254 can be varied.

The focusing lens 274 is provided to receive a plurality of laser lightpulses from the mirror 268 and to focus each of the laser light pulses.In one exemplary embodiment, the focusing lens 274 has a focal length of40 millimeters. In alternative embodiments, the focusing lens 274 has afocal length of 50 millimeters and 80 millimeters. Of course, thefocusing lens 274 can have focal lengths between 40-80 millimeters, orless than 40 millimeters, or greater than 80 millimeters.

The focusing device 278 is provided to move the mirror 268 eitherupwardly or downwardly towards the mastering tool 254 to adjust a focalpoint of the laser light pulse relative to the mastering tool 254, basedon a control signal from the controller 284. The focusing device 278 isphysically coupled to both the carriage device 276 and the focusing lens274 and is electrically coupled to the controller 284.

The carriage device 276 is provided to move the mirror 268, the focusingdevice 278, and the focusing lens 274 from the end 253 to the end 255 ofthe mastering tool 254, based on the control signal from the controller284. It should be noted that during operation when the carriage device276 is stopped at an axial position relative to the mastering tool 254,the mastering tool 254 can be rotated such that the laser light pulsescan form a plurality of cells around a circumference of the masteringtool 254, before the carriage device 276 moves to another positionrelative to the mastering tool 254. The carriage device 276 isphysically coupled to the mirror 268, the focusing device 278, and thefocusing lens 274, and is electrically coupled to the controller 284.

It should be noted that in an alternative embodiment, the laser 260 isdirectly coupled to the carriage device 276. In this alternativeembodiment, the laser 276 emits laser light pulses to the mirror 268that directs the laser light pulses to the focusing lens 274. Thefocusing lens 274 directs the laser light pulses to the mastering tool254 to form cells on the mastering tool 254.

The motor 280 is provided to rotate the mastering tool 254 about an axis257 at a predetermined speed, in response to control signal from thecontroller 284. The motor 284 is physically coupled of the masteringtool 254 and electrically coupled to the controller 284.

The position sensor 282 is provided to generate a signal indicative of arotational position of the mastering tool 254. The position sensor 282is physically coupled to the mastering tool 254 and electrically coupledto the controller 284.

The controller 284 is provided to control operation of the components ofthe system 250 for forming a plurality of cells on the mastering tool254. In particular, the controller 284 is configured to controloperation of the laser 260, the carriage device 276, the focusing device278, and the motor 280. Further, the controller 284 is configured toreceive amplitude values from the signal generator 270 and to generatecontrol signals for inducing the actuator 272 to move the mirror 268 todesired operational positions. By varying the amplitude values, theposition of the mirror 262 is varied such that the placement of theplacement of a plurality of cells on the mastering tool 254 is varied.Further, the controller 284 is configured to receive position signalsfrom the position sensor 282, which can be utilized to accuratelyposition the mastering tool 254 at desired rotational positions. Thecontroller 284 includes a CPU, a computer readable medium such as a ROMand a RAM, and an I/O interface (not shown). The CPU executes thesoftware algorithms stored in the computer readable medium forimplementing the control methodology described below with respect tosystem 250.

It should be noted that although the system 250 adjusts an operationalposition of the mirror 268 to vary the placement of the cells on themastering tool 254, that in alternative embodiments any optical device(e.g., laser 260, mirrors 264, 266, or focusing lens 274) within thesystem 250 could have its operational position adjusted utilizing one ormore actuators (not shown) to vary the placement of the cells on themastering tool 254.

It should be noted in an alternative embodiment, a stationary device(not shown is placed in the optical path of the laser light pulses andoptically steers the laser light pulses to vary the placement of thecells on the mastering tool 254, instead of utilizing a movable opticalcomponent (e.g., a movable mirror). An example of such a stationarydevice is an Acousto-Optical Modulator (AOM) that diffracts receivedlaser light pulses in certain directions. In particular, the AOMreceives laser light pulses and controls the mode and the direction ofdiffraction of the laser light pulses based on a high frequencyelectrical signal received by the AOM.

Referring to FIG. 19, a brief explanation of a plurality of cells on amastering tool with cell placement randomization will be explained. Cellplacement randomization refers to a methodology of varying a position oflaser light pulses contacting the mastering tool to generate cells atvarying position error distances with respect to circumferential lineson the mastering tool 254 in accordance with a predetermineddistribution. As shown, the plurality of cells 252 are disposed on amastering tool proximate a circumferential line 288 extending around themastering tool. It should be noted that for purposes of simplicity, thecircumferential line 288 is shown in a 2-D view. Further, the centerpoints of each of the cells in the plurality of cells 252 are disposedat predetermined position error distances from the circumferential line288. For example, the center point 292 of the cell 290 is disposed at aposition error distance (PED1) from the circumferential line 288.Further, for example, the center point 298 of the cell 296 is disposedat a position error distance (PED2) from the circumferential line 296.

Referring to FIG. 20, a plurality of the amplitude values 300 that canbe generated by signal generator 270 is illustrated. Each amplitudevalue of the plurality in amplitude values 320 corresponds to a positionerror value for a cell with respect to a predetermined circumferentialline.

Referring to FIG. 21, a graph 310 illustrates an exemplary distributionof cell position errors for cells relative to circumferential lines of amastering tool that can be obtained utilizing the plurality of theamplitude values 300. In particular, the histogram bar 312 indicatesthat 20 percent of the cells along a circumferential line of themastering tool has a position error distance of −10 microns. Further,the graph 310 indicates that an amplitude value (S3_1) is utilized toinduce the actuator 272 to move the mirror 268 such that a laser lightpulse reflected therefrom forms a cell with a position error distance of−10 microns from a respective circumferential line. Still further, thehistogram bar 316 indicates that 20 percent of the cells along thecircumferential line of the mastering tool have a position errordistance of 10 microns. Further, the graph 310 indicates that anamplitude value (S3_11) is utilized to induce the actuator 272 to movethe mirror 268 such that a laser light pulse reflected therefrom forms acell with a position error distance of 10 microns from the respectivecircumferential line.

Referring to FIG. 22, a plurality of the amplitude values 320 that canbe generated by signal generator 270 is illustrated. Each amplitudevalue of the plurality in amplitude values 300 corresponds to a positionerror value for a cell with respect to a predetermined circumferentialline.

Referring to FIG. 23, a graph 326 illustrates an exemplary distributionof cell position errors for cells (having a 20 micron cell opening size)relative to circumferential lines of a mastering tool that can beobtained utilizing the plurality of amplitude values 320. In particular,the histogram bar 328 indicates that 9 percent of the cells along acircumferential line of the mastering tool has a position error distanceof −10 microns. Further, the graph 326 indicates that an amplitude value(S4_1) is utilized to induce the actuator 272 to move the mirror 268such that a laser light pulse reflected therefrom forms a cell with aposition error distance of −10 microns from the respectivecircumferential line. Further, the graph 326 indicates that an amplitudevalue (S4_11) is utilized to induce the actuator 272 to move the mirror268 such that a laser light pulse reflected therefrom forms a cell witha position error distance of 10 microns from the respectivecircumferential line.

Referring to FIG. 24, a plurality of lines 359 for illustrating anexemplary positioning of center points of cells on the mastering tool254 utilizing a cell placement randomization methodology are provided.Although the plurality of lines 359 extend around the mastering tool254, the lines 359 are illustrated in a 2-D view for purposes ofdiscussion. Each line of lines 359 is equidistant from adjacent lines.It should be further noted that each line of lines 359 extends throughcenter points (not shown) of cells that are disposed intermittentlyaround the mastering tool 254. For example, the line 360 extends throughcenter points of cells that extend around the mastering tool 254 thatare formed when the carriage device 276 is disposed at a first axialposition relative to the mastering tool 254 and the mastering tool 254is rotated 360 degrees. Further, for example, the line 362 extendsthrough center points of cells that extend around the mastering tool 254that are formed when the carriage device 276 is disposed at a secondaxial position relative to the mastering tool 254 and the mastering tool254 is rotated 360 degrees. Further, for example, the line 364 extendsthrough center points of cells that extend around the mastering tool 254that are formed when the carriage device 276 is disposed at a thirdaxial position relative to the mastering tool 254 and the mastering tool254 is rotated 360 degrees. Further, for example, the line 366 extendsthrough center points of cells that extend around the mastering tool 254that are formed when the carriage device 276 is disposed at a fourthaxial position relative to the mastering tool 253 and the mastering tool254 is rotated 360 degrees.

Referring to FIG. 25, a plurality of lines 379 for illustrating anotherexemplary positioning of center points of cells on an alternativeembodiment of the mastering tool 254 utilizing a cell placementrandomization methodology are provided. Although the plurality of lines379 extend around the mastering tool 254, the lines 379 are illustratedin a 2-D view for purposes of discussion. Each line of lines 379 havingvarying distances between adjacent lines. It should be further notedthat each line of lines 379 extends through center points (not shown) ofcells that are disposed intermittently around the mastering tool 254.For example, the line 380 extends through center points of cells thatextend around the mastering tool 254 that are formed when the carriagedevice 276 is disposed at a first axial position relative to themastering tool 254 and the mastering tool 254 is rotated 360 degrees.Further, for example, the line 382 extends through center points ofcells that extend around the mastering tool 254 that are formed when thecarriage device 276 is disposed at a second axial position relative tothe mastering tool 254 and the mastering tool 254 is rotated 360degrees. Further, for example, the line 384 extends through centerpoints of cells that extend around the mastering tool 254 that areformed when the carriage device 276 is disposed at a third axialposition relative to the mastering tool 254 and the mastering tool 254is rotated 360 degrees. Further, for example, the line 386 extendsthrough center points of cells that extend around the mastering tool 254that are formed when the carriage device 276 is disposed at a fourthaxial position relative to the mastering tool 254 and the mastering tool254 is rotated 360 degrees.

Referring to FIGS. 26-30, a method for forming a plurality of cells onthe mastering tool 254 utilizing the system 250 will now be explained.In particular, for purposes of simplicity, the method will describe thesteps for forming first and second cells on the mastering tool 254utilizing the system 250. It should be noted that steps 400-430 describeutilizing a single laser light pulse for forming each respective cell onthe mastering tool 254. Still further, the steps 432-462 are optionalsteps that would only be utilized when additional laser light pulses areutilized for forming the first and second cells on the mastering tool254. Still further, it should be noted, that when the system 250 forms atextured surface on the mastering tool 254, the system 250 would form aplurality of additional cells in the mastering tool 254 utilizing stepssimilar to those described below.

At step 400, the controller 284 induces the motor 280 to rotate themastering tool 254.

At step 401, the position sensor 282 generates a first signal indicativeof a first rotational position of the mastering tool 254 that isreceived by the controller 284.

At step 402, the controller 284 generates a second signal having anamplitude that is based on a first amplitude value when the masteringtool 254 is at the first rotational position. The first amplitude valueis one of a plurality of amplitude values associated with apredetermined distribution of position error distances within a range ofposition error distances, for cells on the mastering tool 254.

At step 404, the actuator 272 moves the moveable mirror 268 to a firstoperational position in response to the second signal.

At step 406, the controller 284 generates a third signal to induce thelaser 260 to emit a first laser light pulse having a first power levelwhen the mastering tool 254 is at the first rotational position.

At step 408, the mirror 264 reflects the first laser light pulse to themirror 266.

At step 410, the mirror 266 reflects the first laser light pulse to themoveable mirror 268.

At step 412, the moveable mirror 268 reflects the first laser lightpulse to the focusing lens 274 when the moveable mirror 268 is at thefirst operational position.

At step 414, the focusing lens 274 focuses the first laser light pulseon the first location of the mastering tool 254 such that the firstlaser light pulse forms a first cell having a first cell opening size atthe first location on the mastering tool 254.

At step 416, the position sensor 282 generates a fourth signalindicative of a second rotational position of the mastering tool 254that is received by the controller 284.

At step 418, the controller 284 generates a fifth signal having anamplitude that is based on a second amplitude value for controlling theposition of the moveable mirror 268 when the mastering tool 254 is atthe second rotational position. The second amplitude value is one of theplurality of amplitude values associated with the predetermineddistribution of position error distances for cells on the mastering tool254.

At step 420, the actuator 272 moves the moveable mirror 268 to a secondoperational position in response to the fifth signal.

At step 422, the controller 284 generates a sixth signal to induce thelaser 260 to emit a second laser light pulse having a second power levelwhen the mastering tool 254 is at the second rotational position.

At step 424, the mirror 264 reflects the second laser light pulse to themirror 266.

At step 426, the mirror 266 reflects the second laser light pulse to themoveable mirror 268.

At step 428, the movable mirror 268 reflects the second laser lightpulse to the focusing lens 274 when the moveable mirror 268 is at thesecond operational position.

At step 430, the focusing lens 274 focuses the second laser light pulseon a second location of the mastering tool 254 such that the secondlaser light pulse forms a second cell having a second cell opening sizeat the second location on the mastering tool 254.

At step 432, the position sensor 282 generates a seventh signalindicative of the first rotational position of the mastering tool 254that is received by the controller 284.

At step 434, the controller 284 generates an eighth signal having anamplitude that is based on the first amplitude value associated with thepredetermined distribution of position error distances for cells on themastering tool 254 when the mastering tool 254 is at the firstrotational position, for controlling the position of the moveable mirror268.

At step 436, the actuator 272 moves the moveable mirror 268 to the firstoperational position in response to the eighth signal.

At step 438, the controller 284 generates a ninth signal to induce thelaser 260 to emit a third laser light pulse having a third power levelwhen the mastering tool 254 is at the first rotational position.

At step 440, the mirror 264 reflects the third laser light pulse to themirror 266.

At step 442, the mirror 266 reflects the third laser light pulse to themoveable mirror 268.

At step 444, the moveable mirror 268 reflects the third laser lightpulse to the focusing lens 274 when the moveable mirror 268 is at thefirst operational position.

At step 446, the focusing lens 274 focuses the third laser light pulseon the first location of the mastering tool 254 such that the thirdlaser light pulse further forms the first cell.

At step 448, the position sensor 282 generates a tenth signal indicativeof the second rotational position of the mastering tool 254 that isreceived by the controller 284.

At step 450, the controller 284 generates an eleventh signal having anamplitude that is based on the second amplitude value associated withthe predetermined distribution of position error distances for cells onthe mastering tool 254 when the mastering tool 254 is at the secondrotational position, for controlling the position of the moveable mirror268.

At step 452, the actuator 272 moves the moveable mirror 268 to thesecond operational position in response to the eleventh signal.

At step 454, the controller 284 generates a twelfth signal to induce thelaser 260 to emit a fourth laser light pulse having a fourth power levelwhen the mastering tool 254 is at the second rotational position.

At step 456, the mirror 264 reflects the fourth laser light pulse to themirror 266.

At step 458, the mirror 266 reflects the fourth laser light pulse to themoveable mirror 268.

At step 460, the moveable mirror 268 reflects the fourth laser lightpulse to the focusing lens 274 when the moveable mirror 268 is at thesecond operational position.

At step 462, the focusing lens 274 focuses the fourth laser light pulseon the second location of the mastering tool 254 such that the fourthlaser light pulse further forms the second cell. After step 462, themethod is exited.

Referring to FIG. 31, a system 470 for forming a plurality of cells on amastering tool 474 is provided. An advantage of the system 470 is thatthe system 470 utilizes a combined cell placement randomization and cellgeometry randomization methodology to vary both the placement of cellsand the opening size of cells on the mastering tool 474 in accordancewith first and second predetermined distributions. As a result, themastering tool 474 has a textured surface that can form a textured filmthat does not have the undesirable banding and patterns discussed above.The system 470 includes a laser 480, a power supply 482, a lightattenuating device 484, a signal generator of 486, mirrors 488, 490,492, a signal generator 494, an actuator 496, a focusing lens 500, acarriage device 502, a focusing device 504, a motor 506, a positionsensor 508, and a controller 510.

The laser 480 is provided to generate a plurality of laser light pulsesthat are used to form a plurality of cells on the mastering tool 474. Inthe illustrated exemplary embodiment, the laser 480 comprises a singlemode Q-switched YAG laser having a substantially similar structure aslaser 60. It should be noted that in alternative embodiments, the laser480 can comprise any known laser capable of forming cells on a masteringtool. For example, in an alternative embodiment the laser 480 cancomprise a single mode continuous-mode Ytterbium fiber laser. The laser480 is controlled via the control signal from the controller 510.Further, the laser 480 receives electrical power from the power supply482.

The signal generator 486 is provided to generate a plurality ofamplitude values that are received by the controller 510 andsubsequently utilized by the controller 510 to induce the lightattenuating device 484 to vary power levels of laser light pulsesutilized to form the plurality of cells. It should be noted that byvarying a power level of laser light pulses, the cell opening sizes andthe cell depths of cells formed on the mastering tool 474 can be varied.

The light attenuating device 484 is provided to attenuate power levelsof a plurality of laser light pulses received from the laser 480, basedon control signals from the controller 510. In particular, the lightattenuating device 484 receives a laser light pulse at a power levelfrom the laser 480 and attenuates the laser light pulse to another powerlevel, based on the control signal from the controller 510. The lightattenuating device 484 is disposed between the laser 480 and the mirror488.

The mirror 488 is provided to receive laser light pulses from the laser480 and to reflect the laser light pulses to the mirror 490. In theillustrated embodiment, the mirror 488 is a stationary mirror. However,in an alternative embodiment, the mirror 488 is configured as a moveablemirror whose position can be changed based on a control signal from thecontroller 510, to vary a direction of reflected laser light pulsestoward the mirror 490.

The mirror 490 is provided to receive laser light pulses from the mirror488 and to reflect the laser light pulses to the mirror 492. In theillustrated embodiment, the mirror 490 is a stationary mirror. However,in an alternative embodiment, the mirror 490 is configured as a moveablemirror whose position can be changed based on a control signal from thecontroller 510, to vary a direction of reflected laser light pulsestoward the mirror 492.

The mirror 492 is provided to receive laser light pulses from the mirror490 and to reflect the laser light pulses to the focusing lens 500. Themirror 492 is coupled to the carriage device 502 that moves the mirror492 generally parallel to the mastering tool 474 from an end 473 to anend 475 of the mastering tool 474. The actuator 496 is operably coupledto the mirror 492 and is provided to rotate the mirror 492 to desiredoperational positions, based upon control signals from the controller510.

The signal generator 494 is provided to generate a plurality ofamplitude values that are received by the controller 510 andsubsequently utilized by the controller 510 to generate control signalsto induce the actuator 496 to move the mirror 492 to desired operationalpositions to form the plurality of cells at desired locations on themastering tool 474. It should be noted that by varying the operationalposition of the mirror 492, the placement of the plurality of cells onthe mastering tool 474 can be varied.

The focusing lens 500 is provided to receive a plurality of laser lightpulses from the mirror 492 and to focus each of the laser light pulses.In one exemplary embodiment, the focusing lens 500 has a focal length of40 millimeters. In alternative embodiments, the focusing lens 500 has afocal length of 50 millimeters and 80 millimeters. Of course, thefocusing lens 500 can have focal lengths between 40-80 millimeters, orless than 40 millimeters, or greater than 80 millimeters.

The focusing device 504 is provided to move the mirror 492 eitherupwardly or downwardly towards the mastering tool 474 to adjust a focalpoint of the laser light pulse relative to the mastering tool 474, basedon a control signal from the controller 510. The focusing device 504 isphysically coupled to both the carriage device 502 and the focusing lens500 and is electrically coupled to the controller 510.

The carriage device 502 is provided to move the mirror 492, the focusingdevice 504, and the focusing lens 500 from the end 473 to the end 475 ofthe mastering tool 474, based on the control signal from the controller510. It should be noted that during operation when the carriage device502 is stopped at a position relative to the mastering tool 474, themastering tool 474 can be rotated such that the laser light pulses canform a plurality of cells around a circumference of the mastering tool474, before the carriage device 502 moves to another axial positionrelative to the mastering tool 474. The carriage device 502 isphysically coupled to the mirror 492, the focusing device 504, and thefocusing lens 500, and is electrically coupled to the controller 510.

It should be noted that in an alternative embodiment, the laser 480 andthe light attenuating device 484 are directly coupled to the carriagedevice 502. In this alternative embodiment, the laser 480 emits laserlight pulses to the light attenuating device 484 that directs the laserlight pulses to the moveable mirror 492. The moveable mirror 492 directsthe laser light pulses to the focusing lens 500. The focusing lens 500directs the laser light pulses to the mastering tool 474 to form cellson the mastering tool 474.

The motor 506 is provided to rotate the mastering tool 474 about an axis507 at a predetermined speed, in response to control signal from thecontroller 510. The motor 506 is physically coupled to the masteringtool 474 and electrically coupled to the controller 510.

The position sensor 508 is provided to generate a signal indicative of arotational position of the mastering tool 474. The position sensor 508is physically coupled to the mastering tool 474 and is electricallycoupled to the controller 510.

The controller 510 is provided to control operation of the components ofthe system 470 for forming a plurality of cells on the mastering tool474. In particular, the controller 510 is configured to controloperation of the laser 480, the carriage device 502, the focusing device504, and the motor 506. Further, the controller 510 is configured toreceive amplitude values from the signal generator 494 and to generatecontrol signals for inducing the actuator 496 to move the mirror 492 todesired operational positions. By varying the amplitude values, theposition of the mirror 492 is varied such that the placement of theplacement of a plurality of cells on the mastering tool 474 is varied.Still further, the controller 510 is configured to receive amplitudevalues from the signal generator 486 for controlling the lightattenuating device 484 to vary a power level of emitted laser lightpulses from the device 484. By varying the power level of emitted laserlight pulses from the device 484, the cell opening size of cells formedon the mastering tool 474 are varied. Still further, the controller 510is configured to receive position signals from the position sensor 508,which can be utilized to accurately position the mastering tool 474 atdesired rotational positions. The controller 510 includes a CPU, acomputer readable medium such as a ROM and a RAM, and an I/O interface(not shown). The CPU executes the software algorithms stored in thecomputer readable medium for implementing the control methodologydescribed below with respect to system 470.

Referring to FIG. 32, a brief explanation of a layout of a plurality ofcells on a region of the mastering tool 474 with both cell placementrandomization and cell geometry randomization will be explained. Asshown, the plurality of cells 472 are disposed on the mastering tool 474proximate a circumferential line 520 that extends around the masteringtool 474. It should be noted that for purposes of simplicity, thecircumferential line 520 is shown in a 2-D view. Further, the centerpoints of each of the cells in the plurality of cells 472 are disposedat predetermined position error distances from the circumferential line520. For example, the center point 524 of the cell 522 is disposed at aposition error distance (PED3) from the circumferential line 520. Thecell 522 also has a diameter (DIAM3). Further, for example, the centerpoint 528 of the cell 526 is disposed at a position error distance(PED4) from the circumferential line 520, which is less than theposition error distance (PED3). The cell 526 also has a diameter (DIAM4)that is greater than the diameter (DIAM3) of the cell 522.

Referring to FIGS. 33-38, a method for forming a plurality of cells onthe mastering tool 474 utilizing the system 470 will now be explained.In particular, for purposes of simplicity, the method will describe thesteps for forming first and second cells on the mastering tool 474utilizing the system 470. It should be noted that steps 540-578 describeutilizing a single laser light pulse for forming each respective cell onthe mastering tool 474. Still further, the steps 580-618 are optionalsteps that would only be utilized when additional laser light pulses areutilized for forming the first and second cells on the mastering tool474. Still further, it should be noted, that when the system 470 forms atextured surface on the mastering tool 474, the system 470 would form aplurality of additional cells in the mastering tool 474 utilizing stepssimilar to those described below.

At step 540, the controller 510 induces the motor 506 to rotate themastering tool 474.

At step 540, the position sensor 508 generates a first signal indicativeof a first rotational position of the mastering tool 474 that isreceived by the controller 510.

At step 542, the controller 510 generates a second signal having anamplitude that is based on a first amplitude value when the masteringtool 474 is at the first rotational position. The first amplitude valueis one of a plurality of amplitude values associated with a firstpredetermined distribution of position error distances within a range ofposition error distances, for cells on the mastering tool 474.

At step 544, the actuator 496 moves the moveable mirror 492 to a firstoperational position in response to the second signal.

At step 546, the controller 510 generates a third signal having anamplitude that is based on a second amplitude value when the masteringtool 474 is at the first rotational position. The second amplitude valueis one of a plurality of amplitude values associated with a secondpredetermined distribution of cell opening sizes within a range of cellopening sizes for the mastering tool 474.

At step 548, the controller 510 generates a fourth signal to induce thelaser 480 to emit a first laser light pulse having a first power level.

At step 550, the light attenuating device 484 attenuates the first laserlight pulse to a second power level in response to the third signal.

At step 552, the mirror 488 reflects the first laser light pulse to themirror 490.

At step 554, the mirror 490 reflects the first laser light pulse to themoveable mirror 492.

At step 556, the moveable mirror 492 reflects the first laser lightpulse to the focusing lens 500 when the moveable mirror 492 is at thefirst operational position.

At step 558, the focusing lens 500 focuses the first laser light pulseon the first location of the mastering tool 474 such that the firstlaser light pulse forms a first cell having a first cell opening size atthe first location on the mastering tool 474.

At step 560, the position sensor 508 generates a fifth signal indicativeof a second rotational position of the mastering tool 474 that isreceived by the controller 510.

At step 562, the controller 510 generates a sixth signal having anamplitude that is based on a third amplitude value for controlling theposition of the moveable mirror 492 when the mastering tool 474 is atthe second rotational position. The third amplitude value is one of theplurality of amplitude values associated with the first predetermineddistribution of position error distances for cells on the mastering tool474.

At step 564, the actuator 496 moves the moveable mirror 492 to a secondoperational position in response to the sixth signal.

At step 566, the controller 510 generates a seventh signal having anamplitude that is based on a fourth amplitude value for controlling thelight attenuating device 484 when the mastering tool 474 is at thesecond rotational position. The fourth amplitude value is one of aplurality of amplitude values associated with the second predetermineddistribution of cell opening sizes within the range of cell openingsizes for the mastering tool 474.

At step 568, the controller 510 generates an eighth signal to induce thelaser 480 to emit a second laser light pulse having a third power levelwhen the mastering tool 474 is at the second rotational position.

At step 570, the light attenuating device 484 attenuates the secondlaser light pulse to a fourth power level in response to the seventhsignal.

At step 572, the mirror 488 reflects the second laser light pulse to themirror 490.

At step 574, the mirror 490 reflects the second laser light pulse to themoveable mirror 492.

At step 576, the moveable mirror 492 reflects the second laser lightpulse to the focusing lens 500 when the moveable mirror 492 is at thesecond operational position.

At step 578, the focusing lens 500 focuses the second laser light pulseon the second location of the mastering tool 474 such that the secondlaser light pulse forms a second cell having a second cell opening sizeat the second location on the mastering tool 474.

At step 580, the position sensor 508 generates a ninth signal indicativeof the first rotational position of the mastering tool 474 that isreceived by the controller 510.

At step 582, the controller 510 generates a tenth signal having anamplitude that is based on the first amplitude value associated with thefirst predetermined distribution of position error distances for cellson the mastering tool 474 when the mastering tool 474 is at the firstrotational position, for controlling the position of the moveable mirror492.

At step 584, the actuator 496 moves the moveable mirror 492 to the firstoperational position in response to the tenth signal.

At step 586, the controller 510 generates an eleventh signal having anamplitude that is based on the second amplitude value associated withthe second predetermined distribution of cell opening sizes within therange of cell opening sizes for the mastering tool 474 when themastering tool 474 is at the first rotational position, for controllingthe light attenuating device 484.

At step 588, the controller 510 generates a twelfth signal to induce thelaser 480 to emit a third laser light pulse having a fifth power level.

At step 590, the light attenuating device 484 attenuates the third laserlight pulse to a sixth power level in response to the eleventh signal.

At step 592, the mirror 488 reflects the third laser light pulse to themirror 490.

At step 594, the mirror 490 reflects the third laser light pulse to themoveable mirror 492.

At step 596, the movable mirror 492 reflects the third laser light pulseto the focusing lens 500 when the moveable mirror 492 is at the firstoperational position.

At step 598, the focusing lens 500 focuses the third laser light pulseon the first location of the mastering tool 474 such that the thirdlaser light pulse further forms the first cell.

At step 600, the position sensor 508 generates a thirteenth signalindicative of the second rotational position of the mastering tool 474that is received by the controller 510.

At step 602, the controller 510 generates a fourteenth signal having anamplitude that is based on the third amplitude value associated with thefirst predetermined distribution of position error distances for cellson the mastering tool 474 when the mastering tool 474 is at the secondrotational position, for controlling the position of the moveable mirror492.

At step 604, the actuator 496 moves the moveable mirror 492 to thesecond position in response to the fourteenth signal.

At step 606, the controller 510 generates a fifteenth signal having anamplitude that is based on the fourth amplitude value associated withthe second predetermined distribution of cell opening sizes within therange of cell opening sizes for the mastering tool 474 when themastering tool 474 is at the second rotational position, for controllingthe light attenuating device 484.

At step 608, the controller 510 generates a sixteenth signal to inducethe laser 480 to emit a fourth laser light pulse having a seventh powerlevel.

At step 610, the light attenuating device 484 attenuates the fourthlaser light pulse to an eighth power level in response to the fifteenthsignal.

At step 612, the mirror 488 reflects the fourth laser light pulse to themirror 490.

At step 614, the mirror 490 reflects the fourth laser light pulse to themoveable mirror 492.

At step 616, the movable mirror 492 reflects the fourth laser lightpulse to the focusing lens 500 when the moveable mirror 492 is at thesecond operational position.

At step 618, the focusing lens 500 focuses the fourth laser light pulseon the second location of the mastering tool 474 such that the fourthlaser light pulse further forms the second cell. After step 618, themethod is exited.

Referring to FIG. 39, a system 630 for forming a plurality of cells on amastering tool 632 is provided. It should be noted that when formingtextured surfaces on a mastering tool such as mastering tool 632, theinventors herein have determined that a change of 2% change or more inan average power of laser light pulses, results in a textured surface onthe mastering tool, having undesirable visible patterns on the masteringtool. An advantage of the system 630 is that the system 630 utilizes acontrol feedback loop to adjust the light attenuating device 644 tooutput laser light pulses having a desired average power level, evenwhen other operational parameters of the system 630 are varying tomaintain the laser light pulses within a desired average power range,with less than a 2% variation in the average power.

The system 630 includes a laser 640, a power supply 642, a lightattenuating device 644, a power monitoring sensor 646, mirrors 648, 650,652, a focusing lens 654, a carriage device 656, a focusing device 658,a motor 660, a position sensor 662, and a controller 664.

The laser 640 is provided to generate a plurality of laser light pulsesthat are used to form a plurality of cells on the mastering tool 632. Inthe illustrated exemplary embodiment, the laser 640 comprises a singlemode Q-switched YAG laser having a substantially similar as laser 60. Itshould be noted that in alternative embodiments, the laser 640 cancomprise any known laser capable of forming cells on a mastering tool.For example, in an alternative embodiment the laser 640 can comprise asingle mode continuous-mode Ytterbium fiber laser. The laser 640 iscontrolled via the control signal from the controller 664. Further, thelaser 640 receives electrical power from the power supply 642.

The light attenuating device 644 is provided to attenuate power levelsof a plurality of laser light pulses received from the laser 640, basedon control signals from the controller 664. In particular, the lightattenuating device 644 receives a laser light pulse at a power levelfrom the laser 640 and attenuates the laser light pulse to another powerlevel, based on the control signal from the controller 664. The lightattenuating device 644 is disposed between the laser 640 and the mirror648.

The power monitoring sensor 646 is provided to monitor an average powerlevel of a plurality of laser light pulses that are transmitted from thelight attenuating device 644. In particular, the power monitoring sensor646 generates a signal indicative of the average power level of theplurality of laser light pulses that are transmitted from the lightattenuating device 644, and the signal is transmitted to the controller664. The controller 664 is configured to compare the measured averagepower level signal received from the power monitoring sensor 646, to adesired reference average power level value. The controller 664 isfurther configured to generate a control signal that is received by thelight attenuating device 664 to adjust the average power level of aplurality of laser light pulses toward the desired reference averagepower level.

The mirror 648 is provided to receive laser light pulses from the lightattenuating device 644 and to reflect the laser light pulses to themirror 650. In the illustrated embodiment, the mirror 648 is astationary mirror. However, in an alternative embodiment, the mirror 648is configured as a moveable mirror whose position can be changed basedon a control signal from the controller 664, to vary a direction ofreflected laser light pulses toward the mirror 650.

The mirror 650 is provided to receive laser light pulses from the mirror648 and to reflect the laser light pulses to the mirror 652. In theillustrated embodiment, the mirror 650 is a stationary mirror. However,in an alternative embodiment, the mirror 650 is configured as a moveablemirror whose position can be changed based on a control signal from thecontroller 664, to vary a direction of reflected laser light pulsestoward the mirror 652.

The mirror 652 is provided to receive laser light pulses from the mirror650 and to reflect the laser light pulses to the focusing lens 654. Themirror 652 is coupled to the carriage device 656 that moves the mirror652 generally parallel to the mastering tool 632 from an end 631 to anend 633 of the mastering tool 632.

The focusing lens 654 is provided to receive a plurality of laser lightpulses from the mirror 652 and to focus each of the laser light pulses.In one exemplary embodiment, the focusing lens 654 has a focal length of40 millimeters. In alternative embodiments, the focusing lens 654 has afocal length of 50 millimeters and 80 millimeters. Of course, thefocusing lens 654 can have focal lengths between 40-80 millimeters, orless than 40 millimeters, or greater than 80 millimeters.

The focusing device 658 is provided to move the mirror 652 eitherupwardly or downwardly towards the mastering tool 632 to adjust a focalpoint of the laser light pulse relative to the mastering tool 632, basedon a control signal from the controller 664. The focusing device 658 isphysically coupled to both the carriage device 656 and the focusing lens654 and is electrically coupled to the controller 664.

The carriage device 656 is provided to move the mirror 652, the focusingdevice 658, and the focusing lens 654 from the end 631 to the end 633 ofthe mastering tool 632, based on the control signal from the controller664. It should be noted that during operation when the carriage device656 is stopped at a position relative to the mastering tool 632, themastering tool 632 can be rotated such that the laser light pulses canform a plurality of cells around a circumference of the mastering tool632, before the carriage device 656 moves to another axial positionrelative to the mastering tool 632. The carriage device 656 isphysically coupled to the mirror 652, the focusing device 658, and thefocusing lens 654, and is electrically coupled to the controller 664.

The motor 660 is provided to rotate the mastering tool 632 about an axis661 at a predetermined speed, in response to control signal from thecontroller 664. The motor 660 is physically coupled to the masteringtool 632 and electrically coupled to the controller 664.

The position sensor 662 is provided to generate a signal indicative of arotational position of the mastering tool 632. The position sensor 662is physically coupled to the mastering tool 632 and is electricallycoupled to the controller 664.

The controller 664 is provided to control operation of the components ofthe system 630 for forming a plurality of cells on the mastering tool632. In particular, the controller 664 is configured to controloperation of the laser 640, the light attenuating device 644, thefocusing device 658, and the motor 660. The controller 664 is furtherconfigured to receive signals from the power monitoring sensor 646 thatthe controller 664 utilizes to adjust subsequent laser light pulsesemitted either from the laser 644 or the light attenuating device 644.The controller 664 includes a CPU, a computer readable medium such as aROM and a RAM, and an I/O interface (not shown). The CPU executes thesoftware algorithms stored in the computer readable medium forimplementing the control methodology described below with respect tosystem 630.

Referring to FIGS. 40-41, a method for forming a plurality of cells onthe mastering tool 632 utilizing the system 630 will now be explained.

At step 670, the controller 664 induces the motor 660 to rotate themastering tool 632.

At step 672, the controller 664 generates a first plurality of signalsto induce the laser 640 to emit a first plurality of laser light pulseshaving a first power level at a first commanded power level.

At step 674, the mirror 648 reflects the first plurality of laser lightpulses to the mirror 650.

At step 676, the mirror 650 reflects the first plurality of laser lightpulses to the mirror 652.

At step 678, the mirror 652 reflects the first plurality of laser lightpulses to the focusing lens 654.

At step 680, the focusing lens 654 focuses the first plurality of laserlight pulses on a first plurality of locations on the mastering tool 632such that the first plurality of laser light pulses forms a firstplurality of cells on the mastering tool 632.

At step 682, the power monitoring sensor 646 measures an average powerlevel associated with the first plurality of laser light pulses.

At step 684, the controller 664 operably communicating with the powermonitoring sensor 646 calculates an average power error value based onthe measured average power level and a desired average power level.

At step 686, the controller 664 calculates a second commanded powerlevel based on the first commanded power level and the average powererror value.

At step 690, the controller 664 generates a second plurality of signalsto induce the laser 640 to emit a second plurality of laser light pulsesat the second commanded power level.

At step 692, the mirror 648 reflects the second plurality of laser lightpulses to the mirror 650.

At step 694, the mirror 650 reflects the second plurality of laser lightpulses to the mirror 652.

At step 696, the mirror 652 reflects the second plurality of laser lightpulses to the focusing lens 654.

At step 698, the focusing lens 654 focuses the second plurality of laserlight pulses on a second plurality of locations on the mastering tool632 such that the second plurality of laser light pulses forms a secondplurality of cells on the mastering tool 632. After step 698, the methodis exited.

The inventive system and method for forming a cell on a mastering toolrepresent a substantial advantage over other systems and methods. Inparticular, the inventive system and method have a technical effect offorming a cell on a mastering tool having an opening size within a rangeof 10-100 micrometers, and an aspect ratio less than or equal to 1.25.

As described above, the methods for forming a plurality of cells on amastering tool can be at least partially embodied in the form ofcomputer-implemented processes and apparatuses for practicing thoseprocesses. In the exemplary embodiments, the methods are embodied incomputer program code executed by one or more controllers. The presentmethods may be embodied in the form of computer program code containinginstructions embodied in one or more computer-readable mediums such asfloppy diskettes, CD-ROMs, hard drives, flash memory, or the like,wherein, when the computer program code is loaded into and executed by acontroller, the controller becomes an apparatus for practicing theinvention.

While the invention is described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalence may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to the teachings of theinvention to adapt to a particular situation without departing from thescope thereof. Therefore, it is intended that the invention not belimited to the embodiments disclosed for carrying out this invention,but that the invention includes all embodiments falling with the scopeof the intended claims. Moreover, the use of the term's first, second,etc. does not denote any order of importance, but rather the term'sfirst, second, etc. are used to distinguish one element from another.

1. A method for forming a cell on a mastering tool, comprising: emittinga first laser light pulse from a laser for a first predetermined timeinterval such that at least a portion of the first laser light pulseforms the cell on the mastering tool, the cell having an opening sizewithin a range of 10-100 micrometers and an aspect ratio less than orequal to 1.25.
 2. The method of claim 1, further comprising receivingthe first laser light pulse at an optical component and directing thefirst laser light pulse from the optical component to the masteringtool.
 3. The method of claim 2, wherein the optical component is atleast one focusing lens.
 4. The method of claim 3, wherein the at leastone focusing lens has a predetermined focal length.
 5. The method ofclaim 4, wherein the predetermined focal length is in a range of 40-80millimeters.
 6. The method of claim 4, wherein the mastering tool is ata distance from the focusing lens less than or equal to thepredetermined focal length of the focusing lens, or greater than thepredetermined focal length of the focusing lens.
 7. The method of claim1, wherein a focused spot of first laser light pulse is at a first depthwithin the mastering tool.
 8. The method of claim 1, further comprisingadjusting a size of the first laser light pulse to a predetermined sizeor a mode shape of the first laser light pulse to a predetermined modeshape, utilizing a first device.
 9. The method of claim 1, wherein thefirst laser light pulse has an average power level within a firstpredetermined average power range.
 10. The method of claim 2, whereinthe first predetermined average power range is 1-100 watts.
 11. A systemfor forming a cell on a mastering tool, comprising: a laser configuredto emit a first laser light pulse for a first predetermined timeinterval such that at least a portion of the first laser light pulseforms the cell on the mastering tool, the cell having an opening sizewithin a range of 10-100 micrometers and an aspect ratio less than 1.25.12. The system of claim 11, further comprising an optical componentconfigured to receive the first laser light pulse from the laser and todirect the first laser light pulse toward the mastering tool.
 13. Thesystem of claim 12, wherein the optical component is at least onefocusing lens.
 14. The system of claim 13, wherein the at least onefocusing lens has a predetermined focal length.
 15. The system of claim14, wherein the predetermined focal length is in a range of 40-80millimeters.
 16. The system of claim 14, wherein the mastering tool isat a distance from the focusing lens less than or equal to thepredetermined focal length of the focusing lens, or greater than thepredetermined focal length of the focusing lens.
 17. The system of claim11, wherein a focused spot of first laser light pulse is at a firstdepth within the mastering tool.
 18. The system of claim 11, furthercomprising a first device configured to either adjust a size of thefirst laser light pulse to a predetermined size or a mode shape of thefirst laser light pulse to a predetermined mode shape.
 19. The system ofclaim 11, wherein the first laser light pulse has an average power levelwithin a first predetermined average power range.
 20. The system ofclaim 19, wherein the first predetermined average power range is 1-100watts.
 21. The system of claim 11, wherein the laser further configuredto emit a second laser light pulse for a second predetermined timeinterval such that at least a portion of the second laser light pulsefurther forms the cell on the mastering tool.
 22. A mastering tool,comprising: a cylindrical drum having at least one cell, the cell havingan opening size within a range of 10-100 micrometers and an aspect ratioless than or equal to 1.25.
 23. A mastering tool, comprising: a platemember having at least one cell, the cell having an opening size withina range of 10-100 micrometers and an aspect ratio less than or equal to1.25.